Stress induced atomic-scale damage and relaxation in bulk metallic glasses

The nanoscale Electric Contact Resistance (nanoECR) system with a high resolution is used to study the possible structural change in bulk metallic glasses (BMGs) after stimulation of cyclic stress. It is found that the electrical current traveling through the fatigue-tested Zr50Cu40Al10 BMG specimen is much lower than that of as-cast one at the same electric voltage. Excluding the effect of sample geometry, it is revealed that the increase in the electric resistivity of the fatigue-tested BMG is due to a more disordered structure. Furthermore, our results show pronounced atomic-scale damage and relaxation in the fatigue-tested BMG, shedding quantitative insights into the process of structural evolution in BMGs under cyclic loadings. (C) 2015 Elsevier B.V. All rights reserved.